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Brown midrib mutants discovered in maize, sorghum and pearl millet through mutagenesis constitute an important genetic resource. Studies indicated that the discovered bmr mutants not only have lower lignin content than their wild-type counterparts, but they are also associated with an improved fodder digestibility and improved process yield in biofuel production. There is need to combine this novel trait with disease resistance to enhance the commercial utilisation of sorghum cultivars by end users. We have assessed reaction of a random set of F 2:4 generations that represented progenies from 46 unique cross combinations involving 12 recurrent parents and 5 donor parents against anthracnose, leaf blight, and charcoal rot diseases. The genotypes were artificially inoculated with the pure cultures of the disease-causing organisms in separate experiments. There were significant genotypic differences for the disease severity and area under disease progress curve (AUDPC) in leaf blight and anthracnose, and number of nodes crossed and lesion length in charcoal rot disease. Progeny expressing bmr12 and bmr6bmr12 were generally superior in resistance to foliar diseases and charcoal rot than bmr6. The reaction of most of the bmr lines against the diseases was similar to their corresponding wild-type parents. Principle component and hierarchical cluster analysis identified sets of genotypes with bmr6 , bmr12 , and bmr6bmr12 loci that combine desirable levels of resistance to two or all the three diseases. These sets of bmr derived lines could be the potential sources to develop disease resistant bmr hybrids and pure line varieties, and improved breeding populations in sorghum. • Lines carrying bmr12 had significantly lower severity for leaf blight disease, followed by lines carrying bmr6bmr12 , bmr6 and wild-type genotypes. • Lines carrying bmr loci (bmr6, bmr12, bmr6bmr12 and Bmr) were not significantly different in response to anthracnose and charcoal rot disease. • Recurrent parent used for forage quality improvement showed no significant effect on the response of bmr derived lines to charcoal rot disease. • Recurrent parent used for forage quality improvement showed a significant effect on the response of bmr derived lines to foliar diseases (leaf blight and anthracnose). [ABSTRACT FROM AUTHOR]

The purpose of this work was to assess biomass and grain yields, path modelling of yield components, and perenniality in 97 Sorghum bicolor x S. halepense (SB x SH) lines, and compare their biomass production to a series of 38 historic (1987–2015) biomass SB trials. Perenniality was evaluated as rhizome overwintering, while other traits were scored using standard procedures. Contrary to SB, several SB x SH lines developed rhizomes and overwintered, depending mostly upon increased dosage of SH genome in SB background. A few backcross-derived SB x SH lines overwintered, indicating that perenniality can be introgressed in sorghum using backcrossing approach. SB x SH lines were competitive in terms of grain and aboveground dry biomass yields compared to SB. SB x SH selections outperformed or were comparable to the best commercial biomass SB hybrid checks, and ranked among the best selections from the historic trials. Grain yield in SB x SH lines depended mainly on number of culms, whereas biomass yields depended mainly on plant height, dry mass and fiber mass fractions of dry material, and number of culms. We identified superior dual purpose SB x SH genotypes producing 5–11 and 38–45 t ha −1 of grain and aboveground biomass, respectively, most of which displayed satisfactory overwintering rates (56–100%) and high levels of fiber (61–69%) mass fraction. These lines represent high energy sorghums suitable for biofuel and food production. The best SB x SH crosses for developing perennial biomass and grain sorghums were represented by perennial/perennial, annual/perennial/perennial, and annual/perennial combinations. [ABSTRACT FROM AUTHOR]

Sorghum crop demonstrated high yield potential under drought and wet environments with a better energy balance than several cultivated plants. Sorghum biomass can contribute to solving the pressing issue of reducing reliance on fossil fuel. Africa and Asia are sorghum centers of diversity, and landraces therefrom can be of great breeding and production interests in the Mediterranean region. Several works evaluated biomass sorghums, but results on comparative performance between lines, landraces and hybrids are lacking. The objective of this work was to assess the performance of these genotypic groups for traits relevant for biofuel conversions, by carrying out a meta-analysis of data from twenty-four trials conducted in different Mediterranean locations in Italy over seven years. Obtained results showed sorghum hybrids as the best biofuel feedstock option as they outperformed landraces and lines for most traits including biomass yield. Landraces represented an attractive alternative to hybrids and lines as they outyielded lines and were second only to hybrids in terms of biomass production and cellulosic content. Biomass yield advantage was explained by increased plant tallness and cellulosic content in hybrids, and cellulosic content in landraces, and to a lesser extent, by plant maturity in hybrids and landraces. Based on biomass quality and quantity, hybrids and landraces can supply thermal, thermochemical and biochemical biofuel conversion industries. Sorghum lines could be better used in first generation biofuel and energy bioconversion technologies requiring lower lignin containing feedstocks. Landraces and lines could be targeted to areas where hybrid seed production industry is not developed. [ABSTRACT FROM AUTHOR]